Objective: The objective of this study was to evaluate effect of denture cleansers on surface roughness and color stability of polyamide and acetal denture base material. Material and methods: Fittydent and Clinsodent cleansing agents were used in this study and a total of (36) samples from polyamide and acetal denture base material were fabricated equally to evaluate their surface roughness and color stability after immersion in the test cleansing agent for immersion periods of 15, 30, and 45 days, respectively. Results:The results of this study revealed that there was no statistical significant difference in surface roughness and color stability of polyamide and acetal thermoplastic resin after immersion in the test cleansing agent for the test period. Conclusion: Usage of Fittydent and Clinsodent cleansing agents will adversely affect surface roughness or color stability of polyamide and acetal denture base material.